Issue #2367747 by Palashvijay4O, andypost, Alienpruts, Cottser, er.pushpinderrana, gaurav.pahuja, pfrenssen, rpayanm, vadim.hirbu: Remove usage of system_rebuild_theme_data()

Issue #2409515 by joelpittet: Updater::findInfoFile() was never updated for .info -> .info.yml change.

Wrong commit message.

This reverts commit 96b7b02e.

Issue #2277103 by tim.plunkett, pwolanin, Wim Leers, dawehner, hotpizzas: Switch Drupal::l() and LinkGenerator to expect a Url object.

Issue #2343651 by xjm, tim.plunkett, Wim Leers, dinarcon, dawehner: Remove most remaining l() calls.

Issue #2300469 by penyaskito | dawehner: Fixed makeBackup() is called without a to parameter in Drupal\Core\Updater\Updater.

Issue #2057259 by alexpott, cweagans, swentel: Fixed Malformed modulename.info.yml file causes fatal error.

Issue #2100329 by cosmicdreams: Use \Drupal instead of Drupal to make IDEs and static code analyse tools happy.

Issue #1608842 by chx, alexpott, sun, effulgentsia, beejeebus, tim.plunkett et al: Replace list of bootstrap modules, enabled modules, enabled themes, and default theme with config.

- Patch #1506630 by Alan Evans, David_Rothstein: Fixed Namedspaced code throws and catches 'Exceptions' which don't exist (causing the DB settings form validation to break on install).

Issue #1323124 by amateescu, aspilicious, Berdir: Convert file transfer system to PSR-0. Commit ALL THE files.

This reverts commit 5abec889.